A Roof System consists of roof rafters, purlins and sheeting panels which are specifically designed to install onto a planned or an existing substructure. The substructure is normally made of concrete or masonry.
When Pebsteel supplies a Roof System it is assumed that the supporting substructure was handled by another professional engineering company and it can withstand the load reactions resulting from the Pebsteel Roof System. The customer’s engineering company must also ensure that its substructure is able to physically accommodate the required Pebsteel anchor bolts and to properly transfer the loads from the Roof System to the foundation.
Potential problems encountered in Roof Systems arise from the incorrect concrete dimensions (at rafter connection elevations) during the construction process. The tolerances required for proper anchor bolts setting (± 5mm) demand extreme care.
Close attention must be given to the interface between the concrete structure and the steel sheeting surface. Irregularities and height variations in the concrete may contribute to building leakage problems in the future.
A Roof System is generally not economical when compared to a complete pre-engineered building, especially for intermediate and large spans. This is due to the fact that the rigid frame action of a pre-engineered steel building distributes stresses optimally throughout the frames resulting in a lighter and more economical overall structure. In a Roof System, stresses are concentrated at the mid-span of the roof rafter that requiring heavier rafters.